Time fuse mechanism for projectiles



13, 1932. A. VARAUD TIME FUSE MECHANISM FOR PROJECTILES Filed July 18. 1932 L/venfaff 4912; Mama? Patented Dec. 13, 1932 arse ANDRE VARAUD, OF GENEVA, SWITZERLAND v TIME FUSE mncnalvrsivrron PRoJ'EoTILEs A Application filed July 18, 1932, Serial No.

The object of the invention is a clock work motion for mechanical time fuses.

In the annexed drawing Fig. 1 is an axial section of the clockwork.

Fig. 2 is a section on line IIII of Fig. 1.

Figs. 3 and 4 illustrate details.

Referring to Fig. 1, 1 indicates a hammer guided in a tube 2 and subjected to the action of a percussion spring 3 and can be locked in the safety position by a bolt 4 engaging in a lateral notch 5 extending over one half of the transverse section of the bolt. This bolt 4 is pivotally mounted on a pivot 6 and is subjected to the action of a back-motion spring 7 acting against a pin 8 carried perpendicularly by the bolt.

Before firing the bolt 4 is normally kept in its active position against the action of the spring 7 by a trigger 9 with spring socket 10 and shifting under the action of inertia at the moment of firing, whilst from this moment to the moment of explosion of the projectile, that is to say during the travel of the latter, this bolt is kept in this active position, against the action of its spring 7 added to that of the centrifugal force, by a toothed crown 11 with internal teeth rotating freely in an annular housing 12 provided in the casing of the clockwork.

Against the rim of the crown 11 a claw 13 of a bolt 4 bears during the time elapsing between the moment when the trigger 9 moves and the moment when the hammer 1 is released. An opening 14 is provided in the said rim at the level of the said claw.

The crown further comprises a pin 15 normally engaging in a corresponding notch 16 of the trigger 9, so as to prevent any accidental displacement of the latter before the winding of the clockwork A situated in the upper part of the mechanism takes place.

At the winding up of the motor spring 17 the crown 11 rotates anti-clockwise, that is to say, in the direction of the arrow 18, through an angle varying from 0 to a little less than 360, according to the length of trajectory which it is desired to obtain, which effects the regulation of the time of firing the fuse. Whilst this movement of the crown 11 is proceeding, the bolt 4 and trigger 9 623,192, and in Switzerland July 25, 1931.

-remain fixed in their respective active positions illustrated in Figs. 1 and 2.

At the moment of the discharge of the projectile, the trigger 9, released from the pin 15, is free to withdraw at the start of firing, at the same time that the clockwork motion is set going, causing the crown 11 to return to zero in the direction of the arrow 19.

When after a time fixed by the timing of the projectile, the opening 14 arrives opposite the claw 13 of the bolt 4, the latter suddenly moves round its pivot 6, releasing the hammer 1 which, under the action of the spring 3, will produce the explosion of the projectile.

Now if the trigger 9 serves as a support to the pin 15 of the crown 11, that is to say, fixes the zero or starting position of the crown a rather serious inconvenience is found in practice. 7

The trigger 9 is in fact held in the active i position by the spring 10, and as it is necessary to provide a certain clearance, seeing that this trigger is required to draw in at the moment of firing by inertia it is clear that, under the action of the pressure exerted on it, through the pin 15, the said trigger will rock and give way more or less, according to the degree of accuracy of its adjustment in the cylinder 20 in which it is guided.

The conditions of manufacture do not permit of guaranteeing the positions of the parts to a hundredth near this pin, which causes comparatively large variations in the position .of the opening 14 of the crown 11 with regard to the end of the claw 13 of the bolt 4 and at the pivotal centre thereof.

On the other hand, this construction and the function performed by trigger 9 necessitate after every attempt at regulating of the clockwork complete dismounting of the latter and a new assembling which is never perfectly similar, in view of the plays of gearings and the position that this pin may assume between one mounting and the next.

These inconveniences are here remedied by the fact that the crown 11, that is to say the rotary driving member, is provided with at least one abutmentco-operating with a fixed abutment integral with the base of the-clock:-

work motion, the position of the crown abutment in relation to that of the notch of the rotary member being such that when it comes into contact with the fixed abutment the retaining bolt of the hammer is capable of being released.

Fig. 3 shows the position of this abutment 21 placed a little behind the pin 15 and Fig. 4 shows a plate 22 integral with the base 23 of the clockwork A andprovided with a fixed abutment 24 for the crown abutment.

Then, and as shown in Fig. 2, the pin 15 enters into the notch 16 of the trigger 9 withrow 18.

.At firing the trigger 9 withdraws and the claw 13 remains supported against the inside of the crown which is driven by the clockwork in the direction of the arrow 19.

2. In mechanism as in claim 1, a claw on the bolt adapted to enter the opening in the crown under the action of centrifugal force and of the spring bolt wherein .the hammer is instantaneously released substantially asidescribed.

ANDRE VARAUD.

Finally, and at the moment that the crown 11 returns to zero, that is to say, when the abutment 21 meets the fixed abutment 24, the craw 13 of the bolt 4enters into the notch 14 under the action of centrifugal force and of the spring 7, whereupon thephammer is instantaneously released.

On the oher hand, when the fuse clockwork motion is tested at the end of mounting in order to regulate it the starting point. of the movement of the crown 11 at the moment of the timing, will invariably be the position of rest when the abutment 21 meets the fixed abutment 24 and this-independently of the plays of gearing and errors of manufacture, which constitutes a great. advantage.

What I claim .as my. invention and desire to secure by Letters Patent of the United States is 1. In clockwork time fuse mechanism for projectiles, a framework, clockwork mechanism in the upper part of said framework, a spring governed hammer slidable in the lower part of said framework and having a lateral notch, a spring bolt adapted'to engage in said notch, a spring governed trigger governing the action of said bolt, an internally toothed crown having an opening to which anti-clockwise movement of rotation is imparted by the clockwork, a fixed abutment and an abutment secured to said internally toothed crown in such position-in relation to the opening of the rotary member that when it comes in contact with said fixed abutment the said retaining bolt of the hammer is released. r a 1 

